Matthew Wright's Channel 5 daytime show has been told it did not break any broadcasting regulations, despite running a survey that used the words "mong", "spaz" and "retard".

The Wright Stuff, which aired the item that attracted the most complaints to Ofcom in 2011, has been cleared of breaking rules relating to harm and offence following an investigation by the media regulator.

The 26 April edition of the show featured Wright discussing the comment made by Rupert Murdoch at the Leveson inquiry into press ethics and standards when he described prime minister David Cameron's deceased son as "retarded".

The show then cut to a poll where a female voiceover asked viewers: "According to one survey, what's the most offensive term to describe someone with learning difficulties? a. Mong b. Retard C. Spaz."

The answer, "retard", was subsequently supplied following an ad break. In 2008, a poll by the BBC also concluded that "retard" was the most offensive disability-related word.

"In Ofcom's view, there was editorial justification for including the survey as it related to a panel discussion about the use of the word "retarded", and was unlikely to exceed audience expectations because such a survey is a regular programme feature," said Ofcom.

Ofcom cleared Channel 5, which holds the broadcasting licence and is responsible for all shows aired on its channels, of an official breach of the UK broadcasting rules.

However the media regulator did issue Channel 5 with cautionary guidance to make sure sensitive subjects are handled carefully in the future.

"Guidance was issued to Channel 5 to consider offering further information to viewers to provide more context and minimise the potential for offence," said Ofcom.

The Wright Stuff has been a magnet for Ofcom investigations of late.

Ofcom's investigation is the latest in a string of on-air gaffes that has landed Wright and his show in hot water with the media regulator.

In December, he imitated a catchphrase from the TV detective series Taggart – "There's been another murder" – to describe the death of teenager Liam Aitchison in the Western Isles of Scotland.

The comment prompted more than 2,200 complaints to Ofcom and became the most complained-about TV item of 2011.

In October, Wright was forced into making an on-air apology after asking viewers "Amanda Knox: would ya?", as part of a wider debate about her successful appeal against her Italian conviction for the killing of Meredith Kercher.

Ofcom received more than a dozen complaints that the comments were sexist and objectified women.

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